1. Field of the Invention
The present invention relates generally to an engine mounting structure for vehicles, and more particularly to a structure for mounting and supporting an engine on the body of a front-engine, front-drive type vehicle or a rear-engine, rear-drive type vehicle.
2. Description of the Prior Art
The conventional mounting arrangement of an engine with its crank shaft extending laterally or transversely of the longitudinal direction of a vehicle of the front-engine, front-drive or rear-engine, rear-drive type is shown in FIG. 5 of the accompanying drawings.
In such prior or conventional mounting arrangement, an engine 1 and a transmission 2 are integrally connected together, with the engine mounted at its one end by a rubber mount 3 on a bracket on the vehicle body and with the transmission 2 mounted at the one end thereof connected to the engine 1 by a pair of rubber mounts 4, 5 on similar vehicle body brackets. The transmission 2 has a differential 6 having a driving shaft 7 with the ends thereof coupled via joints 8, 8 to a pair of driving axles 9, 10 which are in turn connected to a pair of traction wheels 11, 12, respectively. Such conventional engine mounting structure has suffered from the following drawbacks resulting from integral connection between the engine 1 and the transmission 2.
Vibrations produced by the laterally arranged engine while it is running and reactive forces from the driving axles while it is revolving, act upon the mounts 3, 4 and 5. The forces include impacts acting upon the driving axle from the road surface, such as during rapid starting or acceleration of the vehicle. Such reactive forces are transmitted through the transmission to the engine connected thereto and act upon the engine mounts. Therefore, in addition to an arrangement for the prevention of engine vibrations, provision must be made for the mounts 3, 4 and 5 to bear reactive forces.
It is preferable and desirable for the mounts 3, 4 and 5 to have a degree of resiliency required for absorbing engine vibrations effectively. From the standpoint of withstanding the reactive forces acting on the engine, however, the mounts should be as rigid as possible, in contrast to the requirement for resiliency to provide engine vibration absorption. As a compromise, the mounts have been made to have a non-linear spring characteristic. Alternatively, there has been provided a stop for preventing large vibrations. With these prior attempts, the engine rubber mounts cannot adequately function as required, and vibrations are transmitted to the vehicle body. As a result, the vehicle compartment will not be protected from vibrations and noises, and the passengers will suffer a lessened degree of comfort. It has therefore long been desired to provide vehicles of the above-described type with an improved engine mounting structure.
The present invention effectively solves the foregoing problems attendant prior engine mounting structures in front-engine, front-drive or rear-engine, rear-drive vehicles.